FIG. 2A is a perspective view schematically illustrating an ordinary layered ceramic capacitor, FIG. 2B is a cross-sectional view taken along line A-A in FIG. 2A, FIG. 2C is a cross-sectional view taken along line B-B in FIG. 2A, and FIG. 2D is an enlarged schematic cross-sectional view of a region in cover layers (A region) in FIG. 2A.
A layered ceramic capacitor 100 includes a capacitor portion 101, which exhibits capacitance, and external electrodes 103, which are disposed on both ends of the capacitor portion 101.
The capacitor portion 101 includes an effective dielectric portion 109 and cover layers 111. The effective dielectric portion 109 includes dielectric ceramic layers 105 and internal electrode layers 107 that are alternately stacked. The cover layers 111 are disposed on top and bottom surfaces of the effective dielectric portion 109. The cover layers 111 contain a main component the same as the main component of the dielectric ceramic layers 105.
In recent years, there has been a need for further size reduction and capacitance increase of layered ceramic capacitors as mobile information devices are becoming smaller and capable of higher performance.
For this purpose, research has been conducted on layered ceramic capacitors about reducing the thickness of the dielectric ceramic layers 105 and increasing the dielectric constant of the dielectric materials. In addition, an attempt has been made to reduce the thickness of the cover layers 111, which are a constituent of the capacitor portion 101, to increase the volume fraction of the effective dielectric portion 109 (see Patent Literature 1, for example).